This invention relates to a process for representing three-dimensional objects by means of data stored in a computer, which data define a plurality of parallel section surfaces of the object.
West German DE-OS No. 27 38 441 describes a process by which an object is resolved into a series of sections. These sections are offset and displayed, and calculations are performed to generate spatially allocated views in which edge lines in covered portions of the sections are eliminated by means of calculation. The spatial views are viewed in this disclosed system with a stereoscopic arrangement. No indication is given of the algorithm used to eliminate by calculation the covered edges.
In the field of computer-aided design (CAD) it is a known practice to represent objects in perspective form so that covered edges are not visible. However, as is well known, a high expenditure is necessary both in terms of apparatus and calculation to generate this type of representation.
Accordingly, the state of the art does not include a process in which a simple apparatus (for example, the picture screen of a numerically controlled machine tool) can be used to depict a perspective view of a three-dimensional object in such a way that covered edges are not visible. European Application No. EP-A2-0 083 836 discloses a system in a numerically controlled machine tool in which only the tool path is displayed. The expenditure and apparatus required for this is comparatively low.